Doctoring Your Dirt Is Sure to Pay Off in a Healthier Garden

We treat it like dirt and we often ignore it, but the fact is the quality of our soil determines how our gardens grow.

“Although we tend to focus on plants, the health of our soil is critical,” said Vincent Hakes, owner of Huntington Garden Center in Huntington Beach. “A lot of plant problems stem from soil that is out of balance.

“Plants in optimum soil are healthy and ward off pests and diseases,” he said. “When you see a lot of insect and fungus problems, that’s a sign that there is a problem in the soil.”

How do you maintain healthy soil? Unfortunately, there is a lot of conflicting information on soil care and preparation, which makes the process confusing.

But it doesn’t have to be.

“Soil care can be simpler than many people think,” said John Kabashima, environmental horticulture advisor for the University of California Cooperative Extension for Orange and Los Angeles counties. “What you do with your soil will depend on what you intend to plant.”

If you’re planting in an inaccessible area or don’t have much time, plant California natives because they are low maintenance, Kabashima said.

“Native plants have adapted themselves to our climate and soil and have a host of coping mechanisms for surviving, including mycorrhizae fungi, which attach to the roots of plants and develop a mutually beneficial relationship with them. You just plant and let nature do the rest.”

If you plant annual and perennial flowers, vegetables and more tropical plants not native to our climate, here are guidelines for soil care:

* Mulch. It protects the soil from temperature variations and retains moisture. It also makes gardening easier by preventing weeds, providing a good environment for millions of soil organisms and enabling soil to work itself.

“Mulch softens the soil and makes conditions more habitable for the many organisms below the soil surface that do so much for our gardens,” said Julie Hunt, a landscape consultant and arborist who owns Jungle Julie Landscape Solutions in Laguna Hills. “Mulch and the organisms below the soil surface such as earthworms will rototill your soil for you. You’re simulating nature.”

* Amend. Controversy on when to amend, if at all, has heightened in recent years. In general, experts agree you don’t amend for California natives. Many experts also say you should not add amendments to the planting holes of trees or woody shrubs that grow naturally here.

However, they do say you should amend for nonnative shrubs that require acidic, well-draining conditions such as azaleas. Bedding flowers and vegetables also require amendments.

You should also amend when planting in subsoil in new housing developments where the topsoil has been removed.

One amendment most experts suggest using in Southern California gardens is gypsum or gypsite. This is a soil conditioner that improves clay soil by causing the soil’s tiny clay particles to group into larger units or crumbs, improving air circulation and drainage. Gypsum and gypsite also help to wash harmful salts from the soil.

* Break it up. Whether you amend, it’s important you break up the soil, especially if it is heavy clay.

“Loosen the soil to a depth of 2 feet and as wide as possible because plant feeder roots tend to not go deep but spread outwards,” Kabashima said. “The more soil you break up, the farther the roots will go and the healthier the plant will be. This is especially important for trees.”

Work soil when it is moist, never dry or very wet.

To make the process easier, lay down mulch now and in late March or April; the soil will have become moist and very workable.

* Fertilize. There are many types, but many experts agree fertilizer should contain humic acid or humates.

“Humic acid stimulates the soil and makes it alive,” Huntington Garden’s Hakes said. “It helps plants absorb nutrients more efficiently.”

Mulching and the resulting decomposition of organic matter leads to the production of humic acid.

* Huntington Garden Center, Huntington Beach, (714) 963-6522.

* Jungle Julie Landscape Solutions, Laguna Hills, (949) 830-9555.